The immigration bill going through parliament contains a major power grab which would give the Home Office jurisdiction over people's right to marry.
Under the terms of the bill, marriages to non-European Economic Area (EEA) spouses will have to be authorised by the Home Office, rather than the Church.
The move is a major shift of responsibility for marriage from the Church to the state and may worry those MPs and peers who complained about state influence over the institution during the debate on gay marriage.
It gives the Home Office a much more significant role in authorising marriages, rather than limiting its role to the authorisation of spousal visas after the ceremony is conducted.
It means couples seeking to get married will be forced to get authorisation from the state, not the church, if one of them is not from the European Economic Area.
The same will apply to those seeking to get a civil marriage or through other religions.
The immigration bill contains a clause preventing churches starting legal wedding proceedings for couples where one of the partners is a non-EEA citizen.
Instead, clergy will be forced to refer the couple to the Home Office, who they will need to notify of their intention to marry.
The length of time the Home Office has to investigate the marriage is being doubled from 15 days to 30 days, but new rules mean it will be able to extend that period to 70 days if it chooses to. It will then decide if the couple may marry.
The little-commented on section of the bill marks a significant encroachment by the state on what was traditionally the Church's remit.
Civil liberties campaigners warned the move may be a pre-emptive attempt to take overall control of the process underlying marriage.
They referred back to a legal challenge to a 'certificate of approval' needed for civil marriages where one partner was a non-EEA citizen.
That move was deemed unlawful under Article 12 of the Human Rights Act, which guarantees the right to marry, but it also fell foul of discrimination laws because it only applied to civil marriages.
Today's proposals suggest the coalition is starting to bring new elements of marriage under Home Office control, in a bid to overturn the legal ruling.
Critics say that members of the clergy will be forced to check the nationality of those coming to them for marriages, so they can ensure both people are EEA citizens.
Some worry this will turn clergy into de-facto immigration officers, in much the same way as GPs and landlords are being asked to investigate the immigration status of those they come into contact with.
"Last time we checked the home secretary approved visas – not marriages," Liberty policy director Isabella Sankey told Politics.co.uk.
"Along with landlords and bank managers, civil registrars and clergy will be transformed into immigration officials and required to check on British citizens and foreign nationals alike.
"With non-whites and those with ‘'oreign-sounding' names the inevitable targets, this bureaucratic bill is a race relations nightmare waiting to happen."
The move also prevents churches from delivering the banns of marriage for people marrying non-EEA nationals.
The banns of marriage are traditional announcements of a marriage read out in the parish the couple were born in and the one they plan to marry in.
"We accept that if the new procedure is to be introduced for certain non-EEA nationals it is logical to remove the possibility of banns of marriage for that category of cases," a Church of England spokesperson told Politics.co.uk.
"Whether introducing the procedure is proportionate to the undoubted problem of sham marriages is, however, more doubtful given that it will add to the bureaucracy that many people seeking perfectly genuine marriages will face.
"We have made it clear to the Home Office that while clergy can ascertain people’s nationality by asking to see passports, as they already do under guidance issued by the House of Bishops in 2011, they cannot check immigration status."
The immigration bill is having its second reading in the Commons today.